Spark-plug.



W., E. & G. HAGSTROM. SPARK PLUG.

APPLIGATION FILED NOV. 24. 1909.

Patented June 6, 1911.

5&

\ .Ny 3 m ia-STRQIVI Brit-3311 A. GiBBPGRATIDh KANSAS.

gFARln T seen-e Specification of} Application filed November 24,

letters Patent.

which is preferably cup-shaped with its cup To all whom it may concern:

Be it known that we, W ILLIAM l'L-aes'rnou. EMAN URL l-Laosrnozir, andGuerra] iIlAG" s'rnoiu, inventor citizens of the United States ofAmerica, and residents or Lindsbore! Mi'zllhe county, State of liePatented June 6, 191 1.

Serial No. 529,663.

' cing upward, as shown in Fig. 3.

The bottom of the casing A has an enlargcd opening A,

quite so large the result th .entm in new and useful which lip isproi'cme ts in S Plugs, of which the prel'erahly of following is aSPLPliiij-li'lfifl. 7 whi e l (hui or ion lates to sparl-c plugs andinner l r us i movements in such desmall 1h respect to construe out. (1'

n. rts that will pre- =ch devices. Such ll many inon being a i-ulil'tlsor upon some of arts that sluuild. be insulated from each otnc and suchshort-circuiting is, of course. fldvl; it {go to be overcome.

In uccon'ipanyiug drawings lligure l an elevation of a plug at anenlarged size showing the exterior thereof; Fig. 1s longitudinal sectioncorresponding with Fig. l, buthaving the main or central ste n inelevation, and Fig. 3 a detail partly n elevation and partly in sectionat a. still more enlarged scale. for the purpose of showing a collar[1])01'). the central stemof the device which collar may be eitherintegral with the stem, as sl'iown or may he a separate piece upon "hestein.

the said drawin.

i l vices particu k l 4 i L .o the threads C. ti restin on a'shoulder llis body F. This insulating; body I ma be of any insulating material, butis 'ably of porcelain. which is less denihle except for bit-faking thanother is usd the purpose. A Washer G is bottom ofthe inin shoulder whichl' upon the to oi u thin'ible or sleeve H. The insulating bodyF has anauxiliary opening theret-hrough, in which auX- iliary opening is a pinor stem ll provided with. a. collar J in a chamber in the lower part ofthe insulating body F and a nut K on the upper threaded end of the saidstein. Below the collar J is another collar J lip A? washer L per; J toternuna which projection extend ing and oi? the plu within the ca reasonof the upon it, which thirnble, as

is held down l) is preferabl portion than at its per-i opening throughthe center ot. the

which opening is not as thcinternal opening, with at it provides a lip Aon :1 washer L. This washer is the shape shown in Fig.

shape is such that it is thinner at pheiw. A

nits the lower end of the em to 11. a smell pro ection J outside of thecasmS one of the sparking points The washer L lies loosely sing A, and1s held down by thimble or sleeve H resting by the collar G. The washery made of porcelain and is an insulator between the casing A and the endJFof the central stein J. In devices as heretofore made, the metal theshoulder A isually sparking poin suit that i upon the side sh ort .fcarbon or oil should be represented by comes close to the t orprojcctionJ with the redeposited of the projection J and the The bevel on the theWasher L is so arranged splashed upon the botasher L it will run down bygravity away from the central stein i. The

into

projection J.

u iarkiiu point consists of a. stem M the casing A and havingan cct1ngtoward the sparking before dcscribech.

The angle between M and M is an acute angle thus leaving a corner Mwhich is lower than any other part of the inserted point this sp theextreme 9 is that if oil parts it; and

nearest together, the

gravity into a from the siiar ark point does not come The result Theextreme end M of adjacent to spark point 3 but of it. at some little theextreme end of of this construction splashed upon the ace Where they areoil. would run by 11d drop at the extreme end of nd of the should be Jat the pi away from the point M or would run down the point M to thecorner M away king point J It will be seen consequence, an additionalmeans of preventing short-circuiting.

The sectional view in Fig. 2 will show the manner of putting the devicetogether, which may preferably be stated as follows: The washer L isplaced within the casing A and the bushing or-thimble H placed thereon.

The washer or ring G is then placed upon the shoulder E so as to holdthe th imble H down. The central stem is then placed within the centralbody F and secured in place by means of the nut K. The body F is thenplaced within the other case and the nut D screwed down to secure thedifferent parts firmly in position. The device in use usually standsupright in the position shown in the drawings.

'What we claim is: 1. In a spark plug, the combination with a casinghaving .an annular inwardly-extend ing fiange at its lower end, and aninsulating body carried by the casing, of a central stem supported bythe insulating body and having one end projecting through and beyond thelower end of thepasing to form a sparking point said central steinhavi'ng thereon within the casing and adjacent the lowerend of' theinsulating body an invertedcup sha ed guard serving to preventconductingbodies from being conveyed "on said stem beyond suchguard, and aporcelain washer t surrounding the stem and supported the,

annular flange at the lower and of said casmg, said washer havingconcave lower and upper faces.

2-. In a spark plug, the combinatioe witha casing having a washersiipport at the lower end, and an insulating body carried by the casing,of a central stem supported by the insulating body and having one endprojecting through and beyondthelower end of the casing to form asparking point, said central stem having thereon ;withiii the casing aninverted cup-shaped guard serving to prevent conducting bodiesfI'OIH.l)B1I1g I conveyed on said stem beyond such guard, and aporcelain washer mountedkon said surrounding washer support of thecasing and surrounding the stem, said washer .having concave upper andlower faces, asaand for the purpose described;

Signed at Lindsborg, Kans. this 17 th' day of Nov. 1909.-

Witnesses:

PAUL CARLSON J. A. Momma.

